could never have done和could not do有什么区别

Question

如题所述

Answer 1

could never have done 意思是“绝对不会做出那样的事”，和品德或承诺有关。属于虚拟语气的应用，未必是针对过去已经发生过的事。
例如：
I could never have done somthing like that to hurt your feeling.

could not do 有两种可能的用法，一是能力有所不及，一是有能力但是不愿意做。同样也没有特定时间的关联性。
例如：
I could not play piano even if I wanted to.
I could not do anything that may ruin my chance of getting that scholarship.

Answer 2

一个是永远做不到，或者永远不能这样做。

后者是，不能做。表示外部条件或者自身“认为”不能做。
e.g.
i could not do anything illegal

Answer 3

could never have done意为：绝不会那样做
could not do指从能力和意愿上讲不能做